items in order and undoing for subs

Now orders are shown in reverse order in which they are handled,
which is actually the order in which they are placed, chronologically.
Also, undoing now correctly removes substitutes and the substituted.

Signed-off-by: Zeljko <zeljko@zwr.fi>
bugfix: compare, do not assign

Signed-off-by: Zeljko <zeljko@zwr.fi>
decrease quantities on button

Signed-off-by: Zeljko <zeljko@zwr.fi>
front page commands via bar code

Signed-off-by: Zeljko <zeljko@zwr.fi>
bugfix: handle unavailable commands correctly

Signed-off-by: Zeljko <zeljko@zwr.fi>
docs: subs

Signed-off-by: Zeljko <zeljko@zwr.fi>
docs commands

Signed-off-by: Zeljko <zeljko@zwr.fi>
docs boxes

These are just a bunch of random numbers.

Signed-off-by: Zeljko <zeljko@zwr.fi>